Standby?...TiVo scared me tonight

My wife tried to watch TV/TiVo tonight and when she used our Harmony 676 to turn on the TV and video switchbox, she got a black screen. When I looked into it, I noticed the TiVo's green and nightlights were out. Not knowing that this might indicate standby (which we've never done), I panicked and pulled the power cable to power cycle it.

I got the normal boot up screen, and then the just a few minutes more screen, and then black again. I actually called TiVo support at this point, but while on hold, decided to start hitting buttons on the remote...and when I hit the TiVo button, I got the rest of the bootup animation and then it was back to normal.

So, other than going through the menus and selecting standby, what the heck would put the TiVo in standby? Could some stray/partial commands from the Harmony put it in standby? Is it normal for it to boot back up in standby if power cycled while in standby?

 

We've had the TiVo for a year and a half and the Harmony for about a year. This has never happened before.